Searches the string @haystack for the first occurrence of the string @needle, limiting the length of the search to @haystack_len.
a nul-terminated string
the maximum length of @haystack in bytes. A length of -1 can be used to mean "search the entire string", like strstr().
the string to search for
a pointer to the found occurrence, or %NULL if not found.
See Implementation
Searches the string @haystack for the first occurrence of the string @needle, limiting the length of the search to @haystack_len.